Substrate processing apparatus and method

ABSTRACT

A substrate processing apparatus, provided with a substrate carrier support to support a substrate carrier thereon. The carrier support comprises a top support surface to support the substrate carrier; a thermally insulating body of thermally insulating material; and, a primary heater to heat the carrier support. The thermally insulating body is provided at least between the support surface and the primary heater.

FIELD

The present disclosure relates to the field of substrate processingapparatus and method. More in particular the disclosure relates to asubstrate processing apparatus, provided with a substrate carriersupport to support a substrate carrier thereon. The carrier supportcomprises a top support surface to support the substrate carrier; athermally insulating body of thermally insulating material; and aprimary heater to heat the carrier support.

BACKGROUND

The simultaneous processing of a plurality of substrates (e.g.,semiconductor wafers) in a vertical batch furnace presents the problemof how to subject all wafers that are stacked into a substrate carrier(e.g., wafer boat) to substantially the same process conditions acrosstheir respective surface areas. One such process condition is thetemperature uniformity. To obtain uniform processing results across thewafers of a batch, each of the wafers thereof may preferably be heatedsubstantially uniformly to a common temperature by heating meansdisposed proximate a side wall of the reaction chamber and proximate atop wall of the reaction chamber.

As regards in particular the upper wafers in the substrate boat, thewafer-to-wafer temperature uniformity is generally not a significantproblem, while the within-wafer temperature uniformity (due toasymmetries in the construction of the furnace) may be enhanced by anoptional boat rotation mechanism. However, in a vertical batch furnace,the temperature uniformity of the lower wafers in the wafer boat mayprove difficult to improve. This may be due to the fact that they arelocated closely to the relatively cold lower door zone of the reactionchamber. To mitigate the effect of their location, a pedestal supportingthe wafer boat from below may be provided with a primary heater forheating the lower wafers.

When the substrates in the substrate carrier may be moved out of thereaction chamber to cool down and to be replaced with fresh substrates,the primary heater may be kept on to decrease the time necessary tostabilize the temperature when the substrate carrier is moved back inthe reaction chamber for a next load. The primary heater may thereforealso heat up the carrier support and surroundings when the carriersupport is outside the reaction chamber. This heat up may lead tonon-uniform heating of the substrate rack, slower cooldown of thesubstrates in the substrate support, and/or distortion of the airflowduring handling of the substrates, which may be unwanted. Also the powerconsumption of the primary heater may be large when the carrier supportis outside the reaction chamber with the primary heater remainingactivated.

SUMMARY

It is an object to provide for an improved substrate processingapparatus and method.

According to an embodiment there is provided an improved substrateprocessing apparatus. The substrate processing apparatus may be providedwith a substrate carrier support to support a substrate carrier thereon.The carrier support may comprise: a top support surface to support thesubstrate carrier; a thermally insulating body of thermally insulatingmaterial; and a primary heater to heat the carrier support. Thethermally insulating body may be provided at least between the supportsurface and the primary heater.

According to a further embodiment there is provided a method,comprising:

providing a substrate processing apparatus provided with a substratecarrier support to support a substrate carrier thereon and comprising:

a top support surface to support the substrate carrier;

a thermally insulating body of thermally insulating material; and,

a primary heater to heat the carrier support, the thermally insulatingbody may be provided at least between the support surface and theprimary heater, the method further comprising:

-   -   supporting a substrate carrier on the carrier support; and,    -   exchanging at least one substrate of the substrate carrier,        while heating the carrier support of the substrate support with        the primary heater.

For purposes of summarizing the invention and the advantages achievedover the prior art, certain objects and advantages of the invention havebeen described herein above. Of course, it is to be understood that notnecessarily all such objects or advantages may be achieved in accordancewith any particular embodiment of the invention. Thus, for example,those skilled in the art will recognize that the invention may beembodied or carried out in a manner that achieves or optimizes oneadvantage or group of advantages as taught or suggested herein withoutnecessarily achieving other objects or advantages as may be taught orsuggested herein.

All of these embodiments are intended to be within the scope of theinvention herein disclosed. These and other embodiments will becomereadily apparent to those skilled in the art from the following detaileddescription of certain embodiments having reference to the attachedfigures, the invention not being limited to any particular embodiment(s)disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims particularly pointing outand distinctly claiming what are regarded as embodiments of theinvention, the advantages of embodiments of the disclosure may be morereadily ascertained from the description of certain examples of theembodiments of the disclosure when read in conjunction with theaccompanying drawings, in which:

FIG. 1 is a schematic cross-sectional side view of a part of a verticalbatch furnace with a primary heater according to an embodiment;

FIG. 2 is an enlarged cross-sectional side view of a substrate carriersupport in a lower part of a reaction chamber with a primary heateraccording to a second embodiment;

FIGS. 3A to 3C schematically illustrate an exemplary vertical thermalfurnace according to a third embodiment;

FIG. 4 is a schematic cross sectional side view of a substrate carriersupport according to a fourth embodiment; and,

FIGS. 5A to 5C depict some results of the substrate carrier supportaccording to FIG. 1, 2, 3A, 3B, 3C or 4 in comparison with the priorart.

DETAILED DESCRIPTION

Although certain embodiments and examples are disclosed below, it willbe understood by those in the art that the invention extends beyond thespecifically disclosed embodiments and/or uses of the invention andobvious modifications and equivalents thereof. Thus, it is intended thatthe scope of the invention disclosed should not be limited by theparticular disclosed embodiments described below. The illustrationspresented herein are not meant to be actual views of any particularmaterial, structure, or device, but are merely idealized representationsthat are used to describe embodiments of the disclosure.

As used herein, the term “substrate” or “wafer” may refer to anyunderlying material or materials that may be used, or upon which, adevice, a circuit, or a film may be formed. The term “semiconductordevice structure” may refer to any portion of a processed, or partiallyprocessed, semiconductor structure that is, includes, or defines atleast a portion of an active or passive component of a semiconductordevice to be formed on or in a semiconductor substrate. For example,semiconductor device structures may include, active and passivecomponents of integrated circuits, such as, for example, transistors,memory elements, transducers, capacitors, resistors, conductive lines,conductive vias, and conductive contact pads.

FIG. 1 schematically illustrate in a cross-sectional side view of a partof a vertical thermal processing furnace 1. The furnace 1 may be of asingle or dual tube type and may include a generally bell jar-shapedreaction tube 10. The reaction tube 10 may delimit a reaction chamber 12defining a reaction space 14 in which substrates, e.g., wafers may beprocessed.

The reaction tube 10 may be encircled or surrounded by a tube heater forheating wafers received in the reaction space 14, such as anelectrically resistive heating coil 18 that is powered by an electricalpower supply (not shown). The tube heater 18 may be secured to athermally insulating sleeve 16 that surrounds or encircles the reactiontube 10. The reaction tube 10 may have a generally tubular, for examplecircular or polygonal, cross-sectional shape, and extend along a centralaxis L. As regards to the manufacturing material, the reaction tube 10may be made of quartz, silicon carbide, silicon or another suitable heatresistant material. At its lower, open end, the reaction tube 10 may besupported on a flange 20 that defines a central furnace opening 22 viawhich a wafer boat 24 may enter and/or exit the reaction chamber 12.

The wafer boat 24 (substrate carrier), which may include a plurality ofslots 26 (e.g., between 10 and 300, preferably between 25 and 250) forholding equally as many substrates, e.g., semiconductor wafers 28 (onlyone of which is shown in FIGS. 1 and 2), may be supported on a topsupport surface 34 of a substrate carrier support 32 (e.g., pedestal) ofa support assembly 30. The substrate carrier support 32 may be mountedon a doorplate or seal cap 42 by means of a bearing 44, e.g., a roller-,fluid- or magnetic bearing.

An elevator or lift (not shown) may be used so that the carrier support32 and the substrate carrier 24 may be raised into and lowered from thereaction chamber 12 at the beginning and end of a treatment,respectively. To ensure that the reaction chamber 12 can be sealed in agas-tight manner, several elastomeric O-rings 46 may be employed in thelower part of the furnace 1, in particular between the reaction tube 10and the flange 20, and between the flange 20 and the door plate 42.

The substrate carrier support 32 may accommodate a primary heater 50.The primary heater 50 may have a power between 0.5 and 10 Kilowatt,preferably between 1 and 6 Kilowatt, and most preferably between 2 and 4Kilowatt. The carrier support 32 may be at least partly filled with athermally insulating body 38 of thermally insulating material. Thethermally insulating material insulates between 0.05 W/mK and 5 W/mK, or0.2 to 2 W/mK, 0.3-1 W/mK.

The thermally insulating body 38 may be provided between the top supportsurface 34 and the primary heater 50 to serve as a heat shield when thesubstrates in the substrate carrier 24 may be moved out of the reactionchamber 12 to cool down and to be replaced with fresh substrates. Theprimary heater 50 may then be kept activated to decrease the timenecessary to stabilize the temperature when the substrate carrier 24 ismoved back in the reaction chamber 12 with a next load. The thickness ofthe thermally insulating body between the support surface 34 and theprimary heater 50 may between 0.5 and 12 cm, preferably between 1 and 8cm and most preferably between 2 and 6 cm.

The insulating body 38 of thermally insulating material may reduce theissue that the primary heater 50 may heat up the carrier support 32 andsurroundings when the carrier support 32 is outside the reaction chamber12. Such heating up may lead to non-uniform heating of the substratecarrier and/or a slower cooldown of the substrates in the substratecarrier. Further it may lead to distortion of the airflow duringhandling of the substrates, which may be unwanted because the distortionmay create upward flow while a downward flow may be preferred to avoidparticle contamination on the substrates 28. Also, the power consumptionof the primary heater 50 may decrease by the insulation when the carriersupport 32 is outside the reaction chamber.

The carrier support 32 may comprises a side plate 36 b. The thermallyinsulating body 38 may be provided between the side plate 36 b and theprimary heater 50 to reduce heat loss through the side plate 36 b whenthe carrier support is outside the reaction chamber 12. It may alsoreduce heat loss through the lower portion of the furnace 1, e.g., thedoor plate 42 and the flange 20 when the reaction chamber 12 is closed.

The carrier support 32 may comprise a bottom plate 36 c and thethermally insulating body 38 may be provided between the bottom plate 36c and the primary heater 50 to reduce heat loss when the carrier support32 is outside the reaction chamber 12. It may also reduce heat lossthrough the lower portion of the furnace 1, e.g., the door plate 42 andthe flange 20 when the reaction chamber is closed. The insulatingmaterial 38 may rest on a base plate 39 that is moveable (rotatable)relative to the walls of container 36 a, b, c.

Underneath the support surface 34, the primary heater 50 may spread outto cover an area that may be smaller or approximately equal to the areaof the top support surface 34. This may be required in order to heat(the lower) wafers 28 in the substrate carrier 24 across their entiresurface.

The primary heater 50 may be fixed within, and substantially surroundedby the insulating body 38. An upwardly extending connection portion 52for (electrically) connecting to the primary heater 50 may be embeddedin the thermally insulating body 38 as well. The thermally insulatingbody 38 may be substantially thermally insulating the primary heater 50from its surrounding.

A motor drive may be provided to rotate the carrier support 32 aroundthe central axis L of the reaction chamber 12. Since the substratecarrier 24 may be connected to the carrier support 32, it may rotate inunison therewith. The door plate 42 and the rest of the fixed structureof the furnace 1, e.g., the reaction tube 10 and the thermallyinsulating sleeve 16, may remain stationary during rotation of container36 a, b, c of the carrier support 32. Base plate 39, insulating body 38,and primary heater 50 may also remain stationary during rotation ofcontainer 36. This may be done by fixedly or rigidly connecting baseplate 39 with insulating body 38 and primary heater 50 to a stationarypart of the furnace 1 that is non-rotatably mounted with respect to therotation axis L of the carrier support 32, such as the doorplate 42.

Alternatively, the rotatable mounted support heater 50 may also beprovided with a dedicated motor drive. The motor drive may be configuredto rotate the primary heater 50 at a different angular velocity or evenin opposite direction than that at which the substrate support 32 isdriven.

The carrier support 32 may comprise an upper plate 36 a, a cylindricalside plate 36 b and a bottom plate 36 c, which plates may beinterconnected to define a generally cylindrical container 36. An outersurface of the upper plate 36 a may define the support surface 34 of thecarrier support 30. The container 36 a, b, c may extend between theupper plate 36 a and the bottom plate 36 c, which body accommodates atleast part of the primary heater 50.

FIGS. 2 to 4 schematically illustrate exemplary vertical thermal furnaceaccording to embodiments. In order not to obscure the discussion ofFIGS. 2 to 4, same reference numerals as in FIG. 1 are used for similarcomponents. It is understood, however, that the physical properties of,and relationships between, the various components depicted in FIGS. 2 to4 may differ from those in FIG. 1. Other components of the verticalthermal furnace shown in FIGS. 2 to 4 may generally be identical tocorresponding components of the above-described conventional furnace 1.

FIG. 2 is an enlarged cross-sectional side view of a substrate carriersupport in a lower part of a reaction chamber with a primary heater 50according to a second embodiment. The primary heater 50 may be rotatablemounted in the second embodiment by the primary heater 50 beingmechanically coupled to the rotatable carrier support 32 so that it maybe easier to construct.

The substrate carrier support 32 may accommodate the primary heater 50and may at least partly be filled with a thermally insulating body 38 ofthermally insulating material. The primary heater 50 may have a powerbetween 0.5 and 10 Kilowatt, preferably between 1 and 6 Kilowatt, andmost preferably between 2 and 4 Kilowatt. The thermally insulatingmaterial insulates between 0.05 W/mK and 5 W/mK, or 0.2 to 2 W/mK, 0.3-1W/mK.

The thermally insulating body 38 may be provided between the top supportsurface 34 and the primary heater 50 to serve as an insulator when thesubstrates in the substrate carrier 24 may be moved out of the reactionchamber 12 to cool down and to be replaced with fresh substrates. Thethickness of the thermally insulating body between the support surface34 and the primary heater 50 may between 0.5 and 12 cm, preferablybetween 1 and 8 cm and most preferably between 2 and 6 cm.

The primary heater 50 may be kept activated to decrease the timenecessary to stabilize the temperature when the substrate carrier 24 ismoved back in the reaction chamber 12 with a next load. The insulatingbody 38 of thermally insulating material may partially prevent that theprimary heater 50 heats up the carrier support 32 and surroundings whenthe carrier support 32 is outside the reaction chamber 12. Such heatingup may otherwise lead to non-uniform heating of the substrate carrier,slower cooldown of the substrates in the substrate carrier, and/ordistortion of the airflow during handling of the substrates which may beunwanted. Also the power consumption of the primary heater 50 maydecrease by the insulation when the carrier support 32 is outside thereaction chamber.

The carrier support 32 may comprises a side plate 36 b. The thermallyinsulating body 38 may be provided between the side plate 36 b and theprimary heater 50 to reduce heat loss through the side plate 36 b whenthe carrier support is outside the reaction chamber 12. Also heat lossthrough the lower portion of the furnace 1 may be reduced when thereaction chamber 12 is closed.

The carrier support 32 may comprise a bottom plate 36 c and thethermally insulating body 38 may be provided between the bottom plate 36c and the primary heater 50 to reduce heat loss through the bottom plate36 c when the carrier support 32 is outside the reaction chamber 12.Also heat loss through the door plate 42 and the flange 20 may bereduced when the reaction chamber is closed. Underneath the supportsurface 34, the primary heater 50 may spread out to cover an area thatmay be smaller or approximately equal to the area of the top supportsurface 34. The primary heater 50 may be able to heat (the lower) wafers28 in the substrate carrier 24 across their entire surface.

The primary heater 50 may be fixed within, and substantially surroundedby the insulating body 38. An upwardly extending connection portion 52for (electrically) connecting to the primary heater 50 may be embeddedin the thermally insulating body 38 as well. The thermally insulatingbody 38 may be substantially thermally insulating the primary heater 50from its surrounding.

A motor drive may be provided to rotate the carrier support 32 aroundthe central axis L of the reaction chamber 12. The door plate 42 and therest of the fixed structure of the furnace 1, e.g., the reaction tube 10and the thermally insulating sleeve 16, may remain stationary duringrotation of container 36 a, b, c of the carrier support 32. Insulatingmaterial 38 and primary heater 50 may rotate with the container 36. Thismay be done by fixedly or rigidly connecting container 36 withinsulating body 38 and primary heater 50. The substrate carrier support32 may be mounted on a doorplate or seal cap 42 by means of a bearing44, e.g., a roller-, fluid- or magnetic bearing. The connection portion52 for (electrically) connecting to the primary heater 50 may beconnected with a connector that allows rotation.

In FIG. 3A, substrates in the substrate carrier 24 supported on thecarrier support 32 may be processed in the reaction chamber 12. Thereaction chamber 12 may be closed with the door plate 42 and thesubstrates may be heated with the tube heater (not shown) and thesupport heater 50.

After the substrates 28 have been processed in the reaction chamber 12the substrates in the carrier support 32 may be moved out of thereaction chamber 12 to cool down (see FIG. 3B). The apparatus maytherefor comprise an actuator constructed and arranged to move at leastone of the heat shield and the carrier support 32 with respect to eachother. For example the apparatus may comprises an elevator 59constructed and arranged to move the carrier support 32 in a verticaldirection in and out of the reaction chamber 12. The elevator 59 mayhave a moving portion 63 which may be moveable along a spindle 65 drivenby a motor 67.

As shown in FIG. 3C, the substrate carrier 24 may be completely movedout of the reaction chamber 12. Subsequently the reaction chamber 12 maybe closed with a reaction chamber door 35. With the reaction chamberdoor 35 closed it may be easier to keep the reaction chamber 12 at thecorrect temperature while not heating the surrounding too much.

FIG. 4 is a schematic cross sectional side view of a substrate carriersupport according to a third embodiment. The substrate carrier support32 may accommodate a primary heater 50 and may at least partly be filledwith a thermally insulating body 38 of thermally insulating material.The thermally insulating material may insulate between 0.05 W/mK and 5W/mK, or 0.2 to 2 W/mK, 0.3-1 W/mK.

The thermally insulating body 38 may be provided between the top supportsurface 34 and the primary heater 50 to serve as a heat shield when thesubstrates in the substrate carrier may be moved out of the reactionchamber to cool down and to be replaced with fresh substrates. Thethickness of the thermally insulating body 38 between the supportsurface 34 and the primary heater 50 may between 0.5 and 12 cm,preferably between 1 and 8 cm and most preferably between 2 and 6 cm.

The primary heater 50 may be kept activated to decrease the timenecessary to stabilize the temperature when the substrate carrier ismoved back in the reaction chamber with a next load. The insulating body38 of thermally insulating material may partially prevent that theprimary heater 50 heats up the carrier support and surroundings when thecarrier support 32 is outside the reaction chamber. Such heating up mayotherwise lead to non-uniform heating of the substrate carrier, slowercooldown of the substrates in the substrate carrier, and/or distortionof the airflow during handling of the substrates which may be unwanted.Also the power consumption of the primary heater 50 may decrease by theinsulation when the carrier support 32 is outside the reaction chamber.

The carrier support 32 may comprises a side plate 36 b. The thermallyinsulating body 38 may be provided between the side plate 36 b and theprimary heater 50 to reduce heat loss through the side plate 36 b whenthe carrier support 32 is outside the reaction chamber 12. It may alsoreduce heat loss through the lower portion of the furnace when thereaction chamber is closed.

The carrier support 32 may comprise a bottom plate 36 c and thethermally insulating body 38 may be provided between the bottom plate 36c and the primary heater 50 to reduce heat loss when the carrier support32 is outside and or inside the reaction chamber. Underneath the supportsurface 34, the primary heater 50 may spread out to cover an area thatmay be smaller or approximately equal to the area of the top supportsurface 34.

The primary heater 50 may be fixed within, and substantially surroundedby the insulating body 38. An upwardly extending connection portion forelectrically connecting to the primary heater may be embedded in thethermally insulating body. The thermally insulating body 38 may besubstantially thermally insulating the primary heater 50 from itssurrounding.

The carrier support 32 may comprises a secondary heater 71 between thesupport surface 34 and the thermally insulating body 38. The secondaryheater 71 may have a surface forming the support surface 34 or may bethermally very well connected to the support surface 34.

The secondary heater 71 may be embedded a little into the thermallyinsulating body 38. This may reduce heat loss to the side plate 36 bclose to the secondary heater 71.

The primary heater 50 may have a heating power larger than the secondaryheater 71. The primary heater 50 may have a power between 0.5 and 10Kilowatt, preferably between 1 and 6 Kilowatt, and most preferablybetween 2 and 4 Kilowatt. The secondary heater 71 may have a powerbetween 0.1 and 3 Kilowatt, preferably between 0.3 and 2 Kilowatt, andmost preferably between 0.5 and 1.2 Kilowatt.

The apparatus may have a reaction chamber (see FIGS. 1, 2, 3A, 3B and3C) defining a reaction space and an opening via which a substratecarrier supported on the carrier support is moveable in said reactionspace. The apparatus may comprises a heat controller 73 to control thetemperature of the carrier support 32.

The heat controller 73 may be operably connected to the secondary heater71 with a secondary heater connector 75 and programmed to switch thesecondary heater 71 off when the substrate carrier 24 is outside thereaction space. The heat controller 73 may be programmed to switch thesecondary heater 71 on when the substrate carrier 32 is inside thereaction space. By this switching of the secondary heater 71 heating up,the environment by the secondary heater 71 may be reduced.

The heat controller 73 may be operably connected to the primary heater50 as well. The heat controller 73 may be operably connected to theprimary heater 50 with a primary heater connector 77 and programmed tokeep the primary heater activated when the substrate carrier 24 isoutside the reaction space. The time necessary for the temperature inthe carrier support 32 to stabilize may be reduced by leaving theprimary heater also on when the carrier support is outside the reactionchamber.

The heat controller 73 as depicted may be provided inside the carriersupport and connected to the rest of the apparatus with a connectionportion 52. The connection portion 52 and the primary and secondaryheater connectors 74, 75 are shown as single cables, however, the cablesmay be provided with double wiring. The heat controller 73 may also beprovided in other parts of the apparatus and connected with the primaryand secondary heater connectors 74, 75 to the primary and secondaryheaters.

The primary heater 50 may spread out to cover an area that may besmaller or equal to the area of the top support surface 34. Thesecondary heater 71 may spread out to cover an area that may be smalleror approximately equal to the area of the top support surface 34 aswell. It may thereby be able to heat (the lower) wafers 28 in thesubstrate carrier 24 across their entire surface. The area of theprimary heater 50 may be larger than the area of the secondary heater71.

In order to optimize the temperature uniformity of the lower wafersfurther, primary heater 50 and/or secondary heater 71 may comprise morethan one zone. The heat generating portion of each zone may be extendingover a part of the top support surface 34. E.g., a first zone may extendover a central region of support surface 34 and a second zone may extendover an outer region of support surface 34.

In another embodiment a first zone may extend over a first tangentiallyextending region of support surface 34 and a second zone may extend overa second tangentially extending region of support surface 34. Each zonemay comprise wiring to the heat controllers 73 to allow for individualcontrol.

Experimental Results

FIGS. 5B and 5C depict some results of the substrate carrier supportaccording to the embodiments in comparison to embodiments according tothe prior art. The figures show what the temperature distribution overthe height of the carrier support from the top surface 34 to the bottomplate 36 c is over time. The line depicted by 0 depicts the temperatureat the lowest level, e.g., the bottom plate 36 c of the carrier supportwhile the line 0.1 depicts the temperature at the highest level, e.g.,the carrier support surface 34 of the carrier support. The lines 0.01 to0.09 depict the temperature of levels equally spaced through the heightof the carrier support.

FIG. 5A shows what the temperature distribution is over the height ofthe carrier support when the carrier support is left to cool downoutside the reactor for about 1 hour and the primary heater is switchedoff during this period. What is shown is that the carrier support at alllevels completely cools down. When doing the next load the carriersupport is moved up and the primary heater may be switched on again. Thestabilization of the temperature, which is shown by all the lines of thetemperature over time becoming horizontal may not be accomplished within1 hour which is by far to long for efficiently operating a verticalfurnace.

In FIG. 5B, it is shown what the temperature distribution is over theheight of the carrier support when the carrier support has a primaryheater and an insulating body according to FIG. 1, 2, 3A, 3B or 3C. Theprimary heater 50 may be kept on when the carrier support is moved outof the reactor. What is shown is that the carrier support at level 0.08to level 0.1 may cool down a bit but far less than in FIG. 5A. Furtherlevel 0.7 (e.g., the level of the primary heater 50) to level 0 (e.g.,the level of the bottom plate 36 c) remain at the same temperature bythe primary heater 50 kept on.

When moving the next load in the reactor, the stabilization of thetemperature, which is shown by all the lines of the temperature overtime becoming horizontal, may be accomplished within minutes since mostof the carrier support was still at the same temperature. This makes itpossible to operate the vertical furnace more quick. In this exampleonly a 3.2 kW primary heater may be used, which shows the efficiency ofthis solution.

In FIG. 5C, it is shown what the temperature distribution over theheight of the carrier support may be when the carrier support has aprimary heater and a secondary heater according to FIG. 4. The primaryheater may be kept on when the carrier support is moved out of thereactor for a next load while the secondary heater may be temporarilyswitched off. What is shown is that the carrier support at level 0.08 tolevel 0.1 (e.g., the level of the secondary heater 71) may cool down abit faster than in FIG. 5B. Further level 0.7 (e.g., the level of theprimary heater 50) to level 0 (e.g., the level of the bottom plate 36 c)may remain at the same temperature because the primary heater may remainon.

When moving the next load in the reactor and switching on the secondaryheater 71, again the stabilization of the temperature, which is shown byall the lines of the temperature over time becoming horizontal, may beaccomplished also within minutes which is much more quick than theexample of FIG. 5A. In this example a secondary heater of 0.9 kW, and aprimary heater of 2.5 kW may be used. The dissipated power in thisexample may be only 20% of the pure secondary heater doing the samewhich proves the efficiency of this solution.

Although illustrative embodiments of the present invention have beendescribed above, in part with reference to the accompanying drawings, itis to be understood that the invention is not limited to theseembodiments. Variations to the disclosed embodiments can be understoodand effected by those skilled in the art in practicing the claimedinvention, from a study of the drawings, the disclosure, and theappended claims.

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure or characteristicdescribed in connection with the embodiment is included in at least oneembodiment of the present invention. Thus, the appearances of thephrases “in one embodiment” or “in an embodiment” in various placesthroughout this specification are not necessarily all referring to thesame embodiment. Furthermore, it is noted that particular features,structures, or characteristics of one or more embodiments may becombined in any suitable manner to form new, not explicitly describedembodiments.

The invention claimed is:
 1. A substrate processing apparatus, providedwith a substrate carrier support to support a substrate carrier thereon,wherein the carrier support comprises: a container comprising an uppertop plate, a side plate, and a bottom plate, the upper top platecomprising a horizontal top support surface to support the substratecarrier; a thermally insulating body of thermally insulating materialcontained within the container; a primary heater comprising a horizontaltop surface to heat the carrier support, wherein the thermallyinsulating body is provided between the horizontal top support surfaceand the horizontal top surface, and wherein the primary heater isembedded within the thermally insulating body; and a connection portionor a primary heater connector connected to the primary heater andextending from a bottom surface of the primary heater, the connectionportion or the primary heater connector at least partially embeddedwithin the thermally insulating body.
 2. The apparatus according toclaim 1, wherein an area of the horizontal top surface is less than anarea of the horizontal top support surface.
 3. The apparatus accordingto claim 1, wherein the thermally insulating body, the primary heater,and the connection portion fill the container.
 4. The apparatusaccording to claim 1, wherein the primary heater is fixed within thethermally insulating body.
 5. The apparatus according to claim 1,wherein the thermally insulating body is thermally insulating theprimary heater from its surrounding.
 6. The apparatus according to claim1, wherein the carrier support comprises a secondary heater between thehorizontal top support surface and the thermally insulating body.
 7. Theapparatus according to claim 6, wherein the primary heater comprises aheating power larger than the secondary heater.
 8. The apparatusaccording to claim 6, wherein the secondary heater has a power between0.1 and 3 Kilowatt.
 9. The apparatus according to claim 6, wherein theapparatus comprises a reaction chamber defining a reaction space and anopening via which a substrate carrier supported on the carrier supportis moveable in said reaction space, wherein the apparatus comprises aheat controller to control the temperature of the carrier support,operably connected to the secondary heater and programmed to switch thesecondary heater off when the substrate carrier is outside the reactionspace.
 10. The apparatus according to claim 9, wherein the heatcontroller is operably connected to the primary heater and programmed tokeep the primary heater activated when the substrate carrier is outsidethe reaction space.
 11. The apparatus according to claim 1, wherein theprimary heater has a power between 0.5 and 10 Kilowatt.
 12. Theapparatus according to claim 1, wherein a thickness of the thermallyinsulating body between the support surface and the horizontal topsurface is between 0.5 and 12 cm.
 13. The apparatus according to claim1, wherein the thermally insulating material insulates between 0.05 W/mKand 5 W/mK.
 14. The apparatus according to claim 1, wherein theapparatus comprises a reaction chamber defining a reaction space and anopening via which a substrate carrier supported on the carrier supportis moveable in said reaction space.
 15. The apparatus according to claim14, wherein an outer surface of the upper top plate defines thehorizontal top support surface of the carrier support and the containerat least partially closes off the reaction space.
 16. The apparatusaccording to claim 14, wherein the apparatus comprises an elevatorconstructed and arranged to move the carrier support in a verticaldirection into the reaction chamber.
 17. The apparatus according toclaim 14, wherein the apparatus comprises a heat controller to controlthe temperature of the carrier support, operably connected to theprimary heater and programmed to keep the primary heater activated whenthe substrate carrier is outside the reaction space.
 18. The apparatusaccording to claim 1, further comprising a substrate carrier connectedto the support surface of the carrier support and that is configured tohold at least one substrate.
 19. The apparatus according to claim 18,wherein the substrate carrier is configured to hold between 10 and 300substrates.
 20. A method, comprising: providing a substrate processingapparatus according to claim 1; supporting a substrate carrier on thecarrier support; and, exchanging at least one substrate of the substratecarrier, while heating the carrier support with the primary heater. 21.The apparatus of claim 1, wherein the carrier support comprises asecondary heater that forms at least part of the horizontal top supportsurface.